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Heat Transfer and Flow on the Squealer Tip of a Gas Turbine BladeExperimental investigations are performed to measure the detailed heat transfer coefficient and static pressure distributions on the squealer tip of a gas turbine blade in a five-bladed stationary linear cascade. The blade is a 2-dimensional model of a modem first stage gas turbine rotor blade with a blade tip profile of a GE-E(sup 3) aircraft gas turbine engine rotor blade. A squealer (recessed) tip with a 3.77% recess is considered here. The data on the squealer tip are also compared with a flat tip case. All measurements are made at three different tip gap clearances of about 1%, 1.5%, and 2.5% of the blade span. Two different turbulence intensities of 6.1% and 9.7% at the cascade inlet are also considered for heat transfer measurements. Static pressure measurements are made in the mid-span and near-tip regions, as well as on the shroud surface opposite to the blade tip surface. The flow condition in the test cascade corresponds to an overall pressure ratio of 1.32 and an exit Reynolds number based on the axial chord of 1.1 x 10(exp 6). A transient liquid crystal technique is used to measure the heat transfer coefficients. Results show that the heat transfer coefficient on the cavity surface and rim increases with an increase in tip clearance. 'Me heat transfer coefficient on the rim is higher than the cavity surface. The cavity surface has a higher heat transfer coefficient near the leading edge region than the trailing edge region. The heat transfer coefficient on the pressure side rim and trailing edge region is higher at a higher turbulence intensity level of 9.7% over 6.1 % case. However, no significant difference in local heat transfer coefficient is observed inside the cavity and the suction side rim for the two turbulence intensities. The squealer tip blade provides a lower overall heat transfer coefficient when compared to the flat tip blade.
Document ID
20000056989
Acquisition Source
Glenn Research Center
Document Type
Preprint (Draft being sent to journal)
Authors
Azad, Gm S. (Texas A&M Univ. College Station, TX United States)
Han, Je-Chin (Texas A&M Univ. College Station, TX United States)
Boyle, Robert J. (NASA Glenn Research Center Cleveland, OH United States)
Date Acquired
September 7, 2013
Publication Date
January 1, 2000
Subject Category
Aircraft Propulsion And Power
Report/Patent Number
ASME Paper-2000-FT-0195
Meeting Information
Meeting: ASME Turbo 2000
Location: Munich
Country: Germany
Start Date: May 8, 2000
End Date: May 11, 2000
Sponsors: American Society of Mechanical Engineers
Funding Number(s)
PROJECT: RTOP 523-26-13
CONTRACT_GRANT: NAG3-2002
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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